- Introducing Certificates of Structural Adequacy (COSA)
- What are they?
- Should you have one?
- Background information.
- Today’s Certificates Of Structural Adequacy.
- Surveyors, Banks and Lenders health warning.
Introducing Certificates of Structural Adequacy or COSA for short
This article explores the topic of Certificates of Structural Adequacy (COSA) within the context of buying and selling a residential property. Specifically, how they relate to a Structural Engineers Report for a buyer or, on occasion, a seller.
Certificates of Structural Adequacy (COSA) were established by the Institution of Structural Engineers in 2000. These certificates are important where a property has either been underpinned or had various structural cracks repaired within the last 20 years. See background below.
A COSA is NOT a form of Guarantee or Warranty and is often misunderstood. It is actually a concise, single-page document summarising relevant events, associated documents, company details, and a list of documentation. See below.
Increasingly, COSAs are requested by buyers’ solicitors, lenders, insurance companies, and surveyors before purchasing a property. See below.
What is a Certificate of Structural Adequacy and what it excludes
A Certificate of Structural Adequacy typically consists of a one-page summary of a major insurance claim related to subsidence. This may involve underpinning and/or significant superstructure crack repairs. Prepared by the lead consultant, the document summarises the entire process from start to finish, including initial reporting, investigations such as soil testing and crack monitoring, as well as the eventual design, specification, and site inspection of the repairs.
Since about 2020, there has been an increasing trend in the request for Certificates of Structural Adequacy during the pre-purchase Structural Engineers Report process. This typically occurs when evaluating cracking, movement issues, or providing advice on potential structural concerns during property transactions, regardless of previous occurrences such as subsidence or underpinning.
At SERL POLE, we issue these certificates clearly outlining their limitations, ensuring that clients fully understand them.
Defining what a COSA is NOT
Crucially the Certificate of Structural Adequacy (COSA) is neither a guarantee nor a warranty. It does not substitute for the guarantee from specialist underpinning or repair contractors, which may still be valid or might have expired. The COSA does not replace the need for a comprehensive Structural Engineer’s Report and can only be issued alongside such a report. Additionally, if the report concludes that the property is not “structurally adequate,” the COSA cannot be issued.
A COSA serves as a summary of the one off visual inspection and issue of a Structural Engineers Report, if that is the extent of the engineers’ evaluation. This excludes any intrusive investigation’s, crack monitoring, or similar activities, which are impractical during the sale process due to time constraints.
A COSA is a useful summary for those who prefer a concise report and do not wish to read the “small print” and the title can convey reassurance and confidence in the findings. This simplicity is likely why solicitors and lenders appreciate the concept.
This additional value of the Certification process does incur a commercial fee as it requires significant professional time and resources to explain the details to all parties involved. It is an extra service over and above our standard structural engineering reports.
It is important for SERL to clarify that the Certificate itself does not confer any contractual obligations beyond what is detailed in the written report, with which it should be read in conjunction. All our professional opinions are included within the formal report, which should be sufficient for most clients without necessitating a Certificate. Nevertheless, demand for COSA Certificates is rising due to the reasons outlined.
Should you have a Certificate of Structural Adequacy?
There is not a simple answer to this question. However, a COSA is becoming increasingly popular particularly amongst those selling their home because they add value to the vendors information pack providing reassurance to the buyer if the property appears sound.
Buyers sometimes obtain a COSA for similar reassurance, however, they are more frequently instructed to do so by their prospective lender or building insurer or via their surveyor.
We advise all our clients to carefully consider the limitations of such a Certificate as they do not provide any guarantee or warranty as detailed in this article.
Background
Since the turn of the millennium, Certificates of Structural Adequacy have been integral to the underpinning and building insurance sector. At that time, the collaboration between the Institution of Structural Engineers and a multi-party group, from the insurance and underpinning industry, determined that major subsidence claims should be summarised by the supervising engineer or loss adjuster.
Certificates of Structural Adequacy (COSA’s) were commonly issued following the underpinning of properties suffering from subsidence and they provided a useful resume of the lengthy Insurance claims process from investigation, design, specification and supervision of repairs.
COSA’s were not generally used by the wider construction or building industry.
COSA’s were not used by Surveyors and Structural Engineers who were not involved in the investigation, specification and supervision of building works.
COSA’s were not used, until very recently, by Structural Engineers carrying out a pre-purchase Structural Engineers Reports, where a one off opinion has been provided but with little or no knowledge of the subsidence history of a property.
The COSA has primarily been used in the insurance industry for procuring subsidence repairs. This involves a series of well-established, detailed procedures to investigate causes and implement suitable remedial actions, requiring the input and expertise of property professionals. Many experts and trades people contribute, including consulting engineers, geologists, arboriculturists, drainage experts, crack monitoring specialists, underpinning professionals, and general contractors. The whole process can often exceed a year. The need for a lead consultant to efficiently summarise the scope, parties involved, and actions taken in one succinct document led to the creation of the COSA in the late 1990s.
The COSA has not replace the professional responsibility of the parties involved and each service provider remains responsible for their advice according to their normal terms of client instructions and terms of business, also backed by their professional indemnity insurance. The specialist underpinning contractors normally provide a 10 year guarantee for their own works.
Today’s Certificate of Structural Adequacy
Since 2020, SERL POLE has noted that institutional lenders, insurance companies, and certain conveyancing solicitors frequently request a Certificate of Structural Adequacy (COSA) for any property purchase. This is regardless of whether there is a history of subsidence or underpinning.
From the above it is immediately clear that this was not the intention of the COSA and there is much misunderstanding even within the professions, regarding its appropriateness.
The limitations of a pre-purchase survey of any sort when the buyer or client is not the owner of the property, time and money constraints, together with all manner of practical implications, mean that it will never be possible to dig holes, test the soil, monitor the cracks for a year, and produce a report which states the property is fine, or structurally adequate.
As Chartered Structural Engineers we are able to assess the strength and stability of a property through a one-off, non-invasive inspection and provide their professional opinion. If a property is deemed “Structurally Adequate,” we will say so. Should the property need clear repairs without further investigations, we outline these in general terms and can confirm “Structural Adequacy” conditional upon such repairs.
By separate agreement beyond the visit and report fee, we can issue a Certificate of Structural Adequacy, provided the client acknowledges its limitations as outlined above. This certificate is not a guarantee or warranty but a summary of the report, with certain convenience and commercial advantages.
Surveyors, Banks and Lenders health warning
We would ask other property professionals to be fully aware of what a COSA is and is not, since they are often called for by lenders and Insurers during the pre-purchase process where RICS Surveyors Reports have recommended a Structural Engineers Report on behalf of the buyer.
It is essential for all parties to understand that when advising a buyer, the structural engineer’s role is limited to a single visit and report. The engineer cannot conduct detailed investigations into structural defects, such as monitoring cracks or testing soil, due to pre-purchase time constraints and because the buyer, not owning the property, is not technically the engineer’s client. As a result, the engineer cannot risk damaging the vendor’s property or create a conflict of interest by serving both buyer and vendor. Some lenders mistakenly request a “Certificate,” believing it provides insurance, indemnity, or warranty, when in fact, it does not exist.
Further Clarification and helpline
If readers of any status whether buying or selling or fellow professionals have any questions regarding this article, we will be very pleased to speak to you, so do not hesitate to call Structural Engineers Reports Limited on 020 8161 9900.
References
1. Subsidence by Institution of Structural Engineers published November 2023.
2. Subsidence of Low Rise Buildings second edition August 2000 Institution of Structural Engineers
